Proof press with chase cart holding means



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Y B #2 m2 wwtmmm PZOmm HIS ATTORNEY PROOF PRESS WITH CHASE CART HOLDING MEANS Filed June 29, 1964 4 Sheets-Sheet i INVENTOR.

FRED \nl. STANDIFORD HIS ATTORNEY United States Patent Otiice 3,296,966 Patented Jan. 10, 1967 3,296,966 PROOF PRESS WITH CHASE CART HOLDING MEANS Fred W. Standiford, Salt Lake (Iity, Utah, assignor to Electro-Aire Corporation, a corporation of Utah Filed June 29, 1964, Ser. No. 378,574 Claims. (Cl. 101269) The present invention relates to the printing industry, and more particularly, to a new and improved, proof-taking press which is versatile in use, highly reliable in operation, and utilizes a new type of platen requiring operating pressures much less than those necessarily needed for proof-press operation.

Accordingly, a principal object of the present invention is to provide a vertical proof-press which accommodates the taking of proofs from a printing form while the latter is borne by a transporting chase cart, and this in a manner such that the bed of the chase cart is effectively clamped into position within the press so as to stabilize the height of the bed of the chase cart, and hence of the printing form, and also to remove loading upon the support structure and casters of the chase cart during proof-taking.

A further object of the invention is to provide clamping means in a vertical proof-press for clamping the top or bed of a chase cart in position for appropriate prooftaking.

A further object of the invention is to provide a clamping mechanism in a vertical proof-press wherein printing form-bearing carts, known as chase carts, are raised above the floor upon which they are rolled so as to confine prooftaking pressure loading to the support structure of the press in the form of compression loading, this without imposing any loading upon the legs or support structure of the case cart proper.

A further object of the invention is to provide an improved vertical proof-press wherein operating pressures are reduced to minimum by providing successive, pressureline patterns of a rocking platen over a printing form suitably disposed thereunder.

A further object is to provide a rockable platen system including an arcuate platen, this provided with a pair of cylinder means having means for appropriately actuating the latter.

A further object is to provide an automatically cycling, arcuate platen having unique means for rocking the platen over a printing from.

A further object of the invention is to provide an improved vertical proof-press having suitable guide means for appropriately positioning a chase cart underneath an operating platen.

The features of the present invention which are believed to be novel are set forth which particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings in which:

FIGURE 1 is a perspective view, partially broken away for convenience of illustration, of a vertical proof-press incorporating the features of the present invention.

FIGURE 2 is a side elevation of the right side of the structure shown in FIGURE 1, this with the side panel broken away to show the interior structure,

FIGURE 3 is a front elevation of the equipment and is taken along the line 3-3 in FIGURE 2.

FIGURE 4A is a detail of certain arcuate structure taken along the arcuate line 4A-4A in FIGURE 3, indicating a modification of the clamping means for clamping a chase cart in position.

FIGURE 4B is an enlarged detail, shown principally in section, and taken along the line 4B-4B in FIGURE 2,

illustrating the co-action of the clamping fingers of the present invention with the printing form or chase cart and the section means associated therewith.

FIGURE 5 is a schematic of a representative pneumatic system which is preferably used in the present invention.

FIGURE 6 is a schematic of the electrical wiring and component diagram associated with the subject matter of FIGURE 5.

FIGURE 7 is a diagram which is a modification addition to that shown in FIGURE 6, this for further making the system completely automatic.

In FIGURE 1 proof-press 10 is shown to include base plate 11 which preferably has a tapered forward edge 12. Side members 13 and 14, together with guide blocks 15 and 16, cooperate to form a passageway 17 for form cart 18, known in the industry as a chase cart. Form cart 18 is conventional in printing establishments and includes plural legs 19, brace structure 20 secured thereto, casters 21 affixed to legs 19, and 'bed or top 22 secured to and supported by the plural legs 19. The construction of the form cart is strictly conventional, and the same, in fact, may take one of several forms. All types of form carts, of course, will include casters, support structure or legs upstanding from and connected thereto, and a bed or table top supported by the supporting structure or legs. Upright support members 23-26 are rigid structural members and are mutually secured together by upper structure 27 over which is disposed platen cover 28. Additionally, side brace structural members 29 and 30 and width brace structural members 31 and 32 further serve to make a rigid interconnecting structure for the upright members 23-26.

Of special importance is the inclusion of rigid angle members 33 and 34 which are preferably rigidly secured, but may be adjustably secured, to the frame structure 35 of which upright members 23-26 and bracing members 29-32 form a part. These angle members are inverted and include chamfered portions 36 and 37 which serve as guides for the press form, not shown, deposited onto bed 22 of cart 18. Depending straps 39 and 40 may be welded to angle members 33 and 34 to serve as guides for the printing cart. A stop-member 41 may be aifixed to the rearmost structural member 31 for disposing the printing cart in a desired position from the form thereon.

Of special importance is the inclusion of plural support fingers 42 and plural support fingers 43, fixedly disposed upon respective shafts 44 and 45. The latter are journaled by appropriate journal blocks 46-49. These latter are welded to angle members 33 and 34, and slots out into these angle members and delineated as 48 are disposed in the angle members for receiving supporting fingers 42.

Also keyed to respective shafts 44 and 45 are levers 50 and 51. A link 52 is connected by pins 53 and 54 to the extremities of levers 50 and 51 for completing the lever structure, and an actuating cylinder 55 is pivoted by pin means 56 to frame structure 35 and includes a piston rod 57 coupled by clevis 58 thereof and pin 59 to a medial point 60 of lever 51.

As thus far described, the structure of the invention operates as follows. The user deposits the required printing form on bed 22 to form cart .18'and subsequently rolls the latter over beveled edge 12 of base plate 11 and into the open area 1 7 between uprights 23-26 to position the cart appropriately beneath the platen P. The cart will be properly guided into the open area, before described, by virture of the guiding act-ion of depending straps 39 and 40, if used, or, if not used, by the structure of inverted angle members 34 and 33. Now in many instances it will be desired that the pressure imposed by the platen onto the cart, when taking a proof of the printing form disposed on the cart, should be removed from the supporting structure of the cart and/or the floor or supporting structure of the fioor or supporting structure ldisposed underneath. Furthermore, it is readily apparent that since different styles of carts are currently used in the printing industry, suitable structure should be provided wherein the top .surface or bed 22 of the form cart will be held at a specific height level in order that a proof may be properly taken from the standard-sized form disposed thereon. Thus, the user will actuate the cylinder 55, either of a hydraulic or pneumatic type (but here shown to be pneumatic), so as to urge lever 51 upwardly in a clockwise direction. The levers t), 51, and link 52, together with their pivot connections, serve to move the levers and linkage structure in order to urge upwardly the supporting fingers 42 against the underside of the form cart. Cylinder 55 will be operated at suflicient pressure so that the required supporting thrust is given to supporting fingers 42 and 43 such as to support completely the weight of the cart, the form thereon, and the same against platen pressure as the same is caused to descend toward and pressure engage the proof-sheet disposed over the press-form, for taking a proof. Accordingly, the proofs will be uni-form since the top of the bed of the form cart will always be held at a uniform height above ground and with respect to the nominal disposition of the platen P, this since the supporting fingers 42 thrust the top of the form cart upwardly into pressure contact with the under-side U of angle members 33 and 34.

After the proof has been taken, the platen is raised in a manner hereinafter described and piston rod 57 withdraws into cylinder 55 so that as to return the sup porting fingers 42 and 43 to the position shown in FIG URE 3. Subsequently, the cart is rolled out of the proof press and the printing form returned to a desired place Note is to be made that in the proof-taking operation, the form never leaves the chase cart.

For adjustment purposes the lever 51 can be journaled rather than pinned to shaft 45. See FIGURE 4B. In such event a separation lever 51 may be keyed to shaft 45 and suitable means such as a block 60 welded to lever 51. Disposed therethrough and engaging the undersurface of lever 51' is adjustment screw 61. Hence, for various size carts which vary in size width-wise the adjustment screw 61 may be adjusted so that corresponding movements of support fingers 42 and 43 are obtained even though the printing cart or truck is disposed slightly off-center with respect to the longitudinal axis of the press.

Our attention is now turned to the printing press or platent structure, see FIGURE 2. Rear platen cylinder 64 includes a piston rod 65 which by clevis 66 is secure-d to cross-bar 67 of the composite platen impression means P. Bolts 68 and 69 may be utilized for purposes of securement. The upper portion of cylinder 65 may be trunnioned by pivot connections 71 to and between opposite trunnion blocks 72.

Correspondingly, the front plate cylinder 74 including piston rod 75 coupled by its clevis 76 to crossabrace 77 of platen P. The upper portion of the cylinder 74 is pivoted by pivot journal means 79 to and between opposite trunnion blocks 80. Trunnion blocks 80 form a part of fixed, spaced beam structure 81 to which the cylinders are respectively trunnioned. The platen P itself is preferably a cast metal part comprising casting 82 and rubber or other resilient cover 83 disposed thereover and secured thereto by attachments 84. I-nking roller 85 is journaled by axle rod 86 to a pair of mutually spaced arms 87, one being shown in FIGURE 2, which are pivoted by journal structure 88 to beam structure 81 and reciprocated by a respective piston rod 89 of cylinder 91). The latter is journaled for pivotal re-orientation displacements by pivot means 91 and bracket 92 afiixed to the beam structure 81. Accordingly, withdrawal of piston rod 89 within cylinders 90 will produce a forward movement (to the left) of the inking roller, see FIGURE 2. When the inking roller has traverse the printing form and comes to its extremity of travel, then by means of limit switch 96, the arm engaging the same may actuate a solenoid valve, hereinafter described, to reverse the pressure within cylinders and return arm 87 to its position shown in FIGURE 2. Rollers 98460 are conventional ink rollers, the operation of which is conventional and the roller 1% of which is driven by a geared motor 101, shown in schematic form in FIGURE 2. In the case of FIGURE 6, the push-button switch 163 is held down until it is desired to return the inking rollers, so limit switch being employed. It is eminently preferable, however, to use a relay R, see FIGURE 7, which, when energized, locks over its own contacts X (normally open) and completes the circuit through contacts Y (also normally open) and solenoid 165 and normally closed limit switch 96 through arm '75 thereof. I

In FIGURE 5 a source of compressed air 195 is coupled by line 106 to pressure regulator 107 the admitted pressure of which is indicated by gage 108 coupled thereto. Regulator 107 is coupled by lines 109 and 110 through conventional air lubricator unit 111 to juncture 112. Lines 113, 1115, 116, and 117 intercouple the air junction line 12 to four-way single solenoid valves 118 and 119 and four-way double solenoid valve 120 as indicated. These solenoid valves, as well as three-way solenoid valve 121, are of conventional manufacture and schematically shown to indicate shuttle communication of the valve with the various lines indicated. The single solenoid valves, i.e. 1.18 and 119, are shown in their energized position wherein lines 113, 114, and 116 respectively communicate with input lines 120, 121, and 122 respectively, which are coupled to the valve as indicated. Line 120 is connected by lines 123 and .124 to the two inking cylinders 90 beneath the respective pistons 90' of the cylinders. Thus, when the solenoid valve 118 is energized (as shown), air is introduced into cylinders 90 via line 113, valve 118, line 1211, and lines 123 and 124 beneath the pistons 90' to urge these pistons rearwardly so as to withdraw piston rods 89. See also FIGURE 2. Now accompanying this air injection beneath pistons 90 is an exhaust of air above the pistons through interconnecting lines 125, 126, and 1127, all interconnecting together as shown in FIGURE 5, and through the valve 118 as indicated, and through line 128 into exhaust manifold 129. Exhaust manifold 129 is coupled to an exhaust mufiler 130 which exhausts air at a specified reduced pressure on the exhaust cycle of the various components of the equipment. Likewise couple to exhaust manifold 129 are lines 131133 leading from respective solenoids 1 18-120, as indicated. Also, it will be seen that lines 134 and 135 are interconnected between solenoid valves 119 and 120, respectively, and the exhaust manifold 129. Lines 136 and 137 are intercoupled through restrictor valve 138 and directly connected to rear platen cylinder 64 beneath piston 64 thereof. Line 139, 121, and 140 lead to the common juncture J. Lines 129, 139, and 121 are interconnected between the cylinder 64 above piston 64' and valve'119 as indicated. Line 140 leading from juncture J is coupled through restrictor valve 141 to the pressure side of pressure switch 142. Pressure switch 142 is normally open, but closes when the air pressure coming in through valve 119, lines 121 and 140, through restrictor valve 141 and line 142, reaches a certain specified, actuating pressure.

Junction 112 is connected by line 143 to three-way solenoid valve 121. Solenoid valve 121 is shown in its energized condition and, when so energized, line 143 is coupled through valve 121 to spring return air cylinder 55 at a point to the right of piston 55'. Air cylinder 55 is the same as that similarly identified in FIGURE 3. Check valve 144 is intercoupled between solenoid valve 121 and the exhaust manifold 129, and restrictor valve 51 is coupled to the exhaust side of cylinder 55.

Before discussing the operation of the pneumatic system illustrated in FIGURE 5 it will be best to consider the wiring diagram of FIGURE 6.

In FIGURE 6 alternating current source .150 impresses an alternating current voltage of, say, 120 volts across leads 151 and 152 coupled thereto. While the switching system may take a sophisticated form, the same is indicated in a simple embodiment so that the same may be easily understood in FIGURE 6. Thus, electrical lead 153 is coupled between lead 151 and switch-arm 154 of switch means 155. Switch contact 156 is coupled by lead 157 through indicator light primary 158, of transformer 159, to lead 152. The secondary 160 of transformer 159 is coupled across the indicator light 161. Disposed in parallel with the previous circuit, as indicated, is a circuit consisting of lead 162 in series with normally open push-button switch 163. The latter is connected by lead 164 through solenoid 165 of the inking cylinders solenoid valve 118 to lead 152. Additionally, line 166 is coupled through coil .167 of a remote starter unit 168, of conventional design, to line 152.

The OFF contact 170 is shown disconnected in FIG- URE 6. The proof contact, see 171, as coupled by lead 172, through push-button switch 173 (which may or may not be suitably interlocked with switch 163) through solenoid 174 of rear platen cylinder solenoid valve 119, see FIGURE 5. Additionally, lead 175 is coupled between contact -171 and lead 152, through primary 176 of indicator light transformer 177. Secondary 178 is coupled through the indicator light 179 as indicated. Remote starter unit 168 includes normally open contacts 179 which are disposed in series with inking cylinder gear motor 101 between leads 151, 152. It will be understood that when the coil 167 is energized, then the normally open contacts will close so as to permit the inking cylinder gear motor to operate. Shunted across normally open contacts 179 is a permissibly included switch 181, usable as an alternate starting means. Switch 182 is disposed in series with fluorescent light 183 in another branch circuit across leads 151, 152.

Another parallel branch is the series circuit including front mercury switch 84 (afiixed to platen P) and, in particular, normally open contacts 185 thereof. Contacts 186 of the pressure switch, see pressure switch 142 in FIGURE 5, are disposed in series with the contacts 185, likewise in series with the A solenoid of solenoid valve 120. A final branch circuit is indicated across leads 151, 152 by a series circuit of rear mercury switch 188 and, in particular, its contacts 189, and the B solenoid of solenoid valve 120. Likewise indicated in end elevation is the platen P and the manner in which the switches are mounted, preferably, on the inside side flanges F of the platen P. Slotted mounts 190 and 191 of the two pressure switches and screws 192 and 193 enable adjustment of the pressure switches so that they will close at the appropriate time.

We are now in a position to discuss the operation of the electro-pneumatic system of the invention.

At the beginning of the cycle switch-arm 154 in FIG- URE 6 is in the OFF position, contacting the contact 170. The operators first task will be to move the form cart 18 into the press as illustrated in FIGURE 1. At this time the closing of switch 195, connected in series with solenoid 121 of solenoid valve 121 and between lines 151, 152 (see FIGURE 6) clamps the bed or table top of the cart by means of the fingers 42, 43 and undersurfaces U of angle members 33 and 34 as hereinbefore explained. This supports the weight of the cart and the printing form disposed thereover against platen pressures as hereinafter to be exerted. Also, it may move upwardly the cart so as to establish the upper surface or bed thereof in the same plane, regardless of the type of truck used.

The operator now shifts arm 154 to the INK position, with arm 154 making contact with the contact 156. At this juncture indicator light 161 goes on, indicating that the system is ready for the inking process. The operator places proof paper from roll R, for example, the cutting mechanism for which is conventional and need not be shown, over the printing form and, subsequently, actuates push-button 163, a normally open switch. When switch 163 is closed, solenoid 165 energizes, producing the energized valve condition for valve 118 as indicated in FIGURE 5. This introduces air beneath the pistons in FIGURE 5 so :as to withdraw the inking roller 85, see'FIGURE 2, over the press form. Before the inking cylinders have sufficient pressure to accomplish this inking function, the remote starter 168 will have been energized, by virtue of its coil 167 to close contacts 179, so that the inking cylinder gear motor 101 will rotate, rotating the inking rollers 99 and and 98 through inking roller 85. This serves to spread ink uniformly over the inking roller 85.

Inking roller 85, hence, is drawn to the right by arms 87 of inking cylinders 90 until limit switch 96 is actuated by the arm (or another member), at which time inking roller 86 is returned to its initial position shown in FIGURE 2. While various holding circuits can be used, one of which is shown in FIGURE 7 and has been heretofore described, nonetheless, the simplified form of the invention shown in FIGURE 6 may apply where, for instance, the push-button 163 is simply held down for the ink cylinders to make their traverse over the plate; return of the inking cylinders can be accomplished simply by releasing the push-button so that the right portion of the shuttle of the valve is translated to the left thus exhausting forwardly of the pistons 90'. Microswitches may or may not be used to accomplish the automatic operation which may be desired. The return of ink rollers is conventional practice in the press art.

Once the printing form is inked as above described, then it becomes necessary to operate the platen. Switch arm 154 is moved to switch contact 171 for the proof cycle. Subsequently, the operator depresses push-button switch 173 to actuate solenoid 174 of a rear platen cylinder 64. For simplicity of discussion, we shall assume that the switch 173 is of a type permitting the operator to depress the same until extension of piston rod 75 of the rear cylinder for pressured contact of platen P is accomplished. Again, holding circuits may be used as needed, also with the cycling of the platen P indicated in FIGURE 6 and the operation of which will be later described.

At this juncture the piston rod 75 will commence to extend, by virtue of the pressure in line 139, so that the rearmost portion RM of the platen, see FIGURE 2, will descend and come in contact with the printing form, press form, or Chase disposed upon the cart, not shown. When the platen engages the press form, the outward movement of piston rod 75 ceases and pressure builds up in line 139 which is transmitted through valve 141 to actuate pressure switch 142, closing contacts 186.

Now the front and rear mercury switches 184 and .188 are so situated and adjusted on the platen that they are normally open when the platen is in a horizontal position. But when the rear of the platen descends through the outward extension of piston rod 75, the front mercury switch closes. However, front mercury switch 184 is ineffective to complete the circuit through solenoid A of the front cylinder solenoid valve until the contacts 186 of pressure switch 142 actually close in the building up of pressure in line 140. Now when the pressure switch does finally close, then, since the front mercury switch is closed at this juncture, the A solenoid of solenoid valve 120 energizes, shown in the energized condition in FIGURE 5, so as to impart pressure above piston 74' of the front cylinder 74. Now at this juncture we shall assume that current has been removed from the solenoid 174, as by return of push-button switch 173 to open condition, of the rear platen cylinder 64. Hence, solenoid 174 is deenergized and the system allowed to exhaust through restrictor valve 138. Restrictor valve 138 is set at a high pressure, however, so that it does allow air to exhaust, but only slowly, while the piston rod 75 of front platen cylinder 74 extends outwardly so as to roll the platen over the printing form. Since both front and rear platen cylinders are trunnioned as illustrated in FIGURE 2 and as has been previously described, the disposition of the rear cylinder is allowed to follow the disposition of the platen in accordance with its rocking response to the descent of piston rod 75 of the front cylinder 74. Now it will be noted that the rear mercury switch is adjusted to remain open during the downward descent of the piston rod 65 of the rear platen cylinder.

' At this point the front cylinder piston rod 75 continues to descend until the form has been completely rolled over by the platen. The rear mercury switch 188 is so adjusted that at this time, for the first time, it closes, thus energizing the B solenoid of solenoid valve 120. The front mercury switch can be so adjusted as to open at the time the rear mercury switch closes. Hence, current in the other solenoid, i.e. solenoid B, will enable the front cylinder to exhaust by pressuring the piston 74 upwardly to withdraw the piston rod 75, and the rear platen cylinder is allowed to return since its solenoid is deenergized and, hence, the piston 64 will return to the top of the cylinder. Use of shock absorber SA, is optional.

The reason for the inclusion of restrictor valve 138 is to restrict quite severely the rate of ascent or return of piston 64 when valve 119 is de-energized. This preserves the pressure in the rear platen cylinder 64, which pressure is maintained throughout the rocking cycle of the platen, though the greater pressure of the front cylinder permits override. The upward withdrawal of piston rod 75 of the front cylinder 74, however, may serve to assisted the'upward ascent of the platen at its rear area, if the piston 64' has not already proceeded to its uppermost position of the former, so that the orientation of the rear cylinder will follow platen orientation as is controlled by the front cylnder, once therocking action of the platen over the printing form has been completed. Again, with appropriate valve and cylinder design, by the time the rocking motion of the platen over the press form is completed, practically all of the air will have passed through the restrictor valve'138 above mentioned so that the rear part of the platen will return with the front part of the platen to its horizontal, raised position at approximately the same time.

In .the simplest form of the invention as indicated in the drawings, the push-button 173 is held down for only the descent of the rear platen cylinder 64.

FIGURE 7 indicates a slight addition and modification of the circuit of FIGURE 6 wherein but an instantaneous depression of switch 173 will commence the cycle automatically and without interruption. In the lower half of FIGURE 7 relay 200 includes normally open contact sets '201 and 202, the former comprising relay interlocking contacts selectively interconnecting a series circuit 263 including normally closed contacts 204 of relay 205, and the lattercompleting the power circuit 206 of the rear platen cylinder solenoid 64.

As will be seen in the lower half of FIGURE 7, contact set 201 simply comprises a means whereby relay '200 locks over its own contacts, sustaining the relay in energized condition even though push-button 173 is subsequently released. This produces a closing of contact set 202 so as to energize the rear cylinder of solenoid 204, to break the locking circuit of relay 200. Hence, relay 200 is de-energized throughout the remainder of the platen rocking cycle.

Another modification of the circuit of FIGURE 6 is indicated in the upper half of FIGURE 7 wherein pushbutton 163 is this time connected in series with the corewinding of relay R, as indicated, and this series circuit is disposed between leads 151 and 152 as indicated. Re-. lay R includes normally open contact sets X and Y, the latter being included in a series circuit including sole noid 165, as indicated, and the former being in a relay locking circuit including the limit switch 96 having normally closed contacts Z, the arm 75 of which is physically aflixed to switch-arm 75 shown in FIGURE 2.

In operation, a momentary depressing of spring-loaded push-button switch 163 energizes relay R and locks the same in energized condition over its own contacts X. Limit switch 96 is normally closed, and the arm of one of the actuating cylinders will open the limit switch momentarily as before described so as to break the locking circuit. When the relay R is and remains energized, solenoid 165 of solenoid valve 118 remains energized. This produces an automatic inking of the printing form disposed upon the chase cart, hereinbefore mentioned. When the limit switch 96 is momentarily opened, the locking switch is interrupted, de-energizing solenoid 165 and permitting the solenoid valve to return to its oppositely conductive state by means of its spring return.

Solenoid valves 118, 119, and 121 each have their respective spring returns as indicated. Solenoid 120, however, has a pair of oppositely acting solenoids which respectively actuate the shuttle thereof into one of two oppositely conducting conditions.

Hence, FIGURE 7 has indicated one way in which momentary actuation of a push-button may produce the inking and return strokings of the inking cylinders. It is also shown that a momentary depression of push-button 173 can commence the rocking action of the platen through its entire cycle and without further manual performance. When the platen completes its cycle, it is ready for re-activation by the actuation, through either manual or automatic sequence, of the push-button switches 163 and 173.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

I claim: 7

1. A proof press including, in combination,;a platen, support structure operatively containing said platen and defining an accessible, open area beneath said platen and configured to receive a cart bearing a printing form, said cart having a bed for bearing said printing form, said support structure including rigid members disposed above the bottom of said support structure, said rigid members being engageable by said cart for determining the height of said bed, means cooperating with said support structure for clamping said cart upwardly againstsaid rigid members to retain said bed at a predetermined height level, means for actuating said clamping-means, and means for actuating said platen to take an impression from said printing form when said cart is clamped by said clamping means against said rigid members;

2. Structure according to claim 1 wherein said rigid members and clamping means are so constructed and arranged that said cart clamped thereby is liftingly clamped against said rigid members into proof-taking position.

3. Structure according to claim 1 wherein said support structure includes a floor base plate beneath said accessible open area, said rigid members and clamping means being so constructed and arranged that said cart when rolled into position upon said base plate is lifted above said base plate and clamped into proof-taking position.

4. Structure according to claim 1 wherein said clamping means comprise a pair of horizontal, mutually spaced pivot rods journaled to said support structure at the sides thereof, clamping finger means affixed to said rods for engaging the underneath side of said bed and thereby urging said bed against said rigid members, an operating cylinder, and linkage means intercoupling said operating cylinder with said pivot rods for pivoting simultaneously said pivot rods in a manner to urge said finger means upwardly against the underneath side of said bed.

5. Structure according to claim 4 wherein those portions of said linkage directly engaging said pivot rods are respectively keyed to said pivot rods.

6. Structure according to claim 1 wherein said rigid members comprise horizontal, parallel, inverted angle members provided with upward flanges directed mutually toward each other.

7. Structure according to claim 1 wherein said rigid members are adjustably secured to said support structure.

8. A proof press including, in combination, impression means, support structure defining an accessible, open area beneath said impression means and configured to receive a cart bearing a printing form, said cart having a bed for bearing said printing form, said support structure including rigid members disposed above the bottom of said support structure, said rigid members being engageable by said cart for determining the height of said bed, means cooperating with said support structure for clamping said cart upwardly against said rigid members to retain said bed at a predetermined height level, means for actuating said impression means to take an impression from said printing form when said cart is clamped by said clamping means against said rigid members.

9. Structure according to claim 8 wherein said rigid members are adjustably secured to said support structure.

10. A proof press including, in combination, a platen, support structure operatively containing said platen and defining an accessible, open area beneath said platen and configured to receive a cart bearing a printing form, said cart having a bed for bearing said printing form, said support structure including rigid members disposed above the bottom of said support structure, said rigid members being engagable by said cart for determining the height of said bed, means cooperating with said support structure for clamping said cart upwardly against said rigid members to retain said bed at a predetermined height level, and means for activating said clamping means.

References Cited by the Examiner UNITED STATES PATENTS 1,032,510 7/1912 Scott 101269 1,655,792 1/1928 Krell 101-65 2,185,998 1/1940 Hufiman 101-250 2,505,184 4/1950 Hill 10l250 2,592,379 4/1952 Barney 101250 2,637,270 5/1953 Bamford 101-152 X 3,090,303 5/1963 Manners et al. 10l269 3,188,949 6/1965 Hill 101-269 ROBERT E. PULFREY, Primary Examiner.

DAVID KLEIN, H. P. EWELL, Examiners. 

10. A PROOF PRESS INCLUDING, IN COMBINATION, A PLATEN, SUPPORT STRUCTURE OPERATIVELY CONTAINING SAID PLATEN AND DEFINING AN ACCESSIBLE, OPEN AREA BENEATH SAID PLATEN AND CONFIGURED TO RECEIVE A CART BEARING A PRINTING FORM, SAID CART HAVING A BED FOR BEARING SAID PRINTING FORM, SAID SUPPORT STRUCTURE INCLUDING RIGID MEMBERS, DISPOSED ABOVE THE BOTTOM OF SAID SUPPORT STRUCTURE, SAID RIGID MEMBERS BEING ENGAGABLE BY SAID CART FOR DETERMINING THE HEIGHT OF SAID BED, MEANS COOPERATING WITH SAID SUPPORT STRUCTURE FOR CLAMPING SAID CART UPWARDLY AGAINST SAID RIGID MEM- 